package ca.michaelmaguire.server.compressurlto.client;

import ca.michaelmaguire.server.compressurlto.shared.FieldVerifier;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class Compressurlto implements EntryPoint
{
	/**
	 * The message displayed to the user when the server cannot be reached or
	 * returns an error.
	 */
	private static final String			SERVER_ERROR	= "An error occurred while "
																+ "attempting to contact the server. Please check your network "
																+ "connection and try again.";

	/**
	 * Create a remote service proxy to talk to the server-side Greeting service.
	 */
	private final GreetingServiceAsync	greetingService	= GWT.create( GreetingService.class );

	/**
	 * This is the entry point method.
	 */
	public void onModuleLoad()
	{
		final Button sendButton = new Button( "Send" );
		final TextBox nameField = new TextBox();
		nameField.setText( "http://www.somelongurl.com/toolong" );
		final Label errorLabel = new Label();

		// We can add style names to widgets
		sendButton.addStyleName( "sendButton" );

		// Add the nameField and sendButton to the RootPanel
		// Use RootPanel.get() to get the entire body element
		RootPanel.get( "nameFieldContainer" ).add( nameField );
		RootPanel.get( "sendButtonContainer" ).add( sendButton );
		RootPanel.get( "errorLabelContainer" ).add( errorLabel );

		// Focus the cursor on the name field when the app loads
		nameField.setFocus( true );
		nameField.selectAll();

		// Create the popup dialog box
		final DialogBox dialogBox = new DialogBox();
		dialogBox.setText( "Remote Procedure Call" );
		dialogBox.setAnimationEnabled( true );
		final Button closeButton = new Button( "Close" );
		// We can set the id of a widget by accessing its Element
		closeButton.getElement().setId( "closeButton" );
		final Label textToServerLabel = new Label();
		final HTML serverResponseLabel = new HTML();
		VerticalPanel dialogVPanel = new VerticalPanel();
		dialogVPanel.addStyleName( "dialogVPanel" );
		dialogVPanel.add( new HTML( "<b>Sending name to the server:</b>" ) );
		dialogVPanel.add( textToServerLabel );
		dialogVPanel.add( new HTML( "<br><b>Server replies:</b>" ) );
		dialogVPanel.add( serverResponseLabel );
		dialogVPanel.setHorizontalAlignment( VerticalPanel.ALIGN_RIGHT );
		dialogVPanel.add( closeButton );
		dialogBox.setWidget( dialogVPanel );

		// Add a handler to close the DialogBox
		closeButton.addClickHandler( new ClickHandler()
		{
			public void onClick( ClickEvent event )
			{
				dialogBox.hide();
				sendButton.setEnabled( true );
				sendButton.setFocus( true );
			}
		} );

		// Create a handler for the sendButton and nameField
		class MyHandler implements ClickHandler, KeyUpHandler
		{
			/**
			 * Fired when the user clicks on the sendButton.
			 */
			public void onClick( ClickEvent event )
			{
				sendNameToServer();
			}

			/**
			 * Fired when the user types in the nameField.
			 */
			public void onKeyUp( KeyUpEvent event )
			{
				if( event.getNativeKeyCode() == KeyCodes.KEY_ENTER )
				{
					sendNameToServer();
				}
			}

			/**
			 * Send the name from the nameField to the server and wait for a response.
			 */
			private void sendNameToServer()
			{
				// First, we validate the input.
				errorLabel.setText( "" );
				String textToServer = nameField.getText();
				if( !FieldVerifier.isValidName( textToServer ) )
				{
					errorLabel.setText( "Please enter at least four characters" );
					return;
				}

				// Then, we send the input to the server.
				sendButton.setEnabled( false );
				textToServerLabel.setText( textToServer );
				serverResponseLabel.setText( "" );
				greetingService.greetServer( textToServer, new AsyncCallback<String>()
				{
					public void onFailure( Throwable caught )
					{
						// Show the RPC error message to the user
						dialogBox.setText( "Remote Procedure Call - Failure" );
						serverResponseLabel.addStyleName( "serverResponseLabelError" );
						serverResponseLabel.setHTML( SERVER_ERROR );
						dialogBox.center();
						closeButton.setFocus( true );
					}

					public void onSuccess( String result )
					{
						dialogBox.setText( "Remote Procedure Call" );
						serverResponseLabel.removeStyleName( "serverResponseLabelError" );
						serverResponseLabel.setHTML( result );
						dialogBox.center();
						closeButton.setFocus( true );
					}
				} );
			}
		}

		// Add a handler to send the name to the server
		MyHandler handler = new MyHandler();
		sendButton.addClickHandler( handler );
		nameField.addKeyUpHandler( handler );
	}
}
